Biology

Omanyte is a small, sky-blue ammonite Pokémon. It has ten tentacles and a pale yellow, helix spiraled shell on its back. The shell's hem has two circular indents, from which Omanyte's large saucer-like eyes protrude. Several gas-filled chambers exist within Omanyte's shell, which it uses to regulate its buoyancy within the water. By evacuating or filling the chambers, it rises and falls while twisting its tentacles to swim. Living on and swimming about the sea floor, it feeds on plankton. If attacked or endangered, it quickly withdraws into its hard shell. Omanyte is considered extinct, although it can be revived from Fossils.

Pokédex entries

Omanyte and Omastar, Kabuto and Kabutops. It is believed these Pokémon became extinct tens of thousands of years ago. The details of their behavior are shrouded in mystery. Though some have speculated that they may still exist, none of these Pokémon have ever been seen alive.